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Diffstat (limited to 'include/jsoncons/config/binary_config.hpp')
| -rw-r--r-- | include/jsoncons/config/binary_config.hpp | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/include/jsoncons/config/binary_config.hpp b/include/jsoncons/config/binary_config.hpp new file mode 100644 index 0000000..51b52a8 --- /dev/null +++ b/include/jsoncons/config/binary_config.hpp @@ -0,0 +1,226 @@ +// Copyright 2017 Daniel Parker +// Distributed under the Boost license, Version 1.0. +// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +// See https://github.com/danielaparker/jsoncons for latest version + +#ifndef JSONCONS_CONFIG_BINARY_CONFIG_HPP +#define JSONCONS_CONFIG_BINARY_CONFIG_HPP + +#include <cfloat> +#include <cstddef> +#include <cstdint> +#include <cstring> // std::memcpy +#include <memory> +#include <type_traits> // std::enable_if + +// The definitions below follow the definitions in compiler_support_p.h, https://github.com/01org/tinycbor +// MIT license + +#ifdef __F16C__ +# include <immintrin.h> +#endif + +#ifndef __has_builtin +# define __has_builtin(x) 0 +#endif + +#if defined(__GNUC__) +#if (__GNUC__ * 100 + __GNUC_MINOR__ >= 403) || (__has_builtin(__builtin_bswap64) && __has_builtin(__builtin_bswap32)) +# define JSONCONS_BYTE_SWAP_64 __builtin_bswap64 +# define JSONCONS_BYTE_SWAP_32 __builtin_bswap32 +# ifdef __INTEL_COMPILER +# define JSONCONS_BYTE_SWAP_16 _bswap16 +# elif (__GNUC__ * 100 + __GNUC_MINOR__ >= 608) || __has_builtin(__builtin_bswap16) +# define JSONCONS_BYTE_SWAP_16 __builtin_bswap16 +# endif +#endif +#elif defined(__sun) +# include <sys/byteorder.h> +#elif defined(_MSC_VER) +// MSVC, which implies sizeof(long) == 4 +# define JSONCONS_BYTE_SWAP_64 _byteswap_uint64 +# define JSONCONS_BYTE_SWAP_32 _byteswap_ulong +# define JSONCONS_BYTE_SWAP_16 _byteswap_ushort +#endif + +namespace jsoncons { +namespace binary { + + struct uint128_holder + { + uint64_t lo; + uint64_t hi; + }; + + static inline bool add_check_overflow(std::size_t v1, std::size_t v2, std::size_t *r) + { + #if ((defined(__GNUC__) && (__GNUC__ >= 5)) && !defined(__INTEL_COMPILER)) || __has_builtin(__builtin_add_overflow) + return __builtin_add_overflow(v1, v2, r); + #else + // unsigned additions are well-defined + *r = v1 + v2; + return v1 > v1 + v2; + #endif + } + + #if defined(__apple_build_version__) && ((__clang_major__ < 8) || ((__clang_major__ == 8) && (__clang_minor__ < 1))) + #define APPLE_MISSING_INTRINSICS 1 + #endif + + inline + uint16_t encode_half(double val) + { + #if defined(__F16C__) && !defined(APPLE_MISSING_INTRINSICS) + return _cvtss_sh((float)val, 3); + #else + uint64_t v; + std::memcpy(&v, &val, sizeof(v)); + int64_t sign = static_cast<int64_t>(v >> 63 << 15); + int64_t exp = (v >> 52) & 0x7ff; + int64_t mant = v << 12 >> 12 >> (53-11); /* keep only the 11 most significant bits of the mantissa */ + exp -= 1023; + if (exp == 1024) { + /* infinity or NaN */ + exp = 16; + mant >>= 1; + } else if (exp >= 16) { + /* overflow, as largest number */ + exp = 15; + mant = 1023; + } else if (exp >= -14) { + /* regular normal */ + } else if (exp >= -24) { + /* subnormal */ + mant |= 1024; + mant >>= -(exp + 14); + exp = -15; + } else { + /* underflow, make zero */ + return 0; + } + + /* safe cast here as bit operations above guarantee not to overflow */ + return static_cast<uint16_t>(sign | ((exp + 15) << 10) | mant); + #endif + } + + /* this function was copied & adapted from RFC 7049 Appendix D */ + inline + double decode_half(uint16_t half) + { + #if defined(__F16C__) && !defined(APPLE_MISSING_INTRINSICS) + return _cvtsh_ss(half); + #else + int64_t exp = (half >> 10) & 0x1f; + int64_t mant = half & 0x3ff; + double val; + if (exp == 0) + { + val = ldexp(static_cast<double>(mant), -24); + } + else if (exp != 31) + { + val = ldexp(static_cast<double>(mant) + 1024.0, static_cast<int>(exp - 25)); + } + else + { + val = mant == 0 ? std::numeric_limits<double>::infinity() : std::nan(""); + } + return half & 0x8000 ? -val : val; + #endif + } + + // byte_swap + + template<class T> + typename std::enable_if<std::is_integral<T>::value && sizeof(T) == sizeof(uint8_t),T>::type + byte_swap(T val) + { + return val; + } + + template<class T> + typename std::enable_if<std::is_integral<T>::value && sizeof(T) == sizeof(uint16_t),T>::type + byte_swap(T val) + { + #if defined(JSONCONS_BYTE_SWAP_16) + return JSONCONS_BYTE_SWAP_16(val); + #else + return (static_cast<uint16_t>(val) >> 8) | (static_cast<uint16_t>(val) << 8); + #endif + } + + template<class T> + typename std::enable_if<std::is_integral<T>::value && sizeof(T) == sizeof(uint32_t),T>::type + byte_swap(T val) + { + #if defined(JSONCONS_BYTE_SWAP_32) + return JSONCONS_BYTE_SWAP_32(val); + #else + uint32_t tmp = ((static_cast<uint32_t>(val) << 8) & 0xff00ff00) | ((static_cast<uint32_t>(val) >> 8) & 0xff00ff); + return (tmp << 16) | (tmp >> 16); + #endif + } + + template<class T> + typename std::enable_if<std::is_integral<T>::value && sizeof(T) == sizeof(uint64_t),T>::type + byte_swap(T val) + { + #if defined(JSONCONS_BYTE_SWAP_64) + return JSONCONS_BYTE_SWAP_64(val); + #else + uint64_t tmp = ((static_cast<uint64_t>(val) & 0x00000000ffffffffull) << 32) | ((static_cast<uint64_t>(val) & 0xffffffff00000000ull) >> 32); + tmp = ((tmp & 0x0000ffff0000ffffull) << 16) | ((tmp & 0xffff0000ffff0000ull) >> 16); + return ((tmp & 0x00ff00ff00ff00ffull) << 8) | ((tmp & 0xff00ff00ff00ff00ull) >> 8); + #endif + } + + template<class T> + typename std::enable_if<std::is_floating_point<T>::value && sizeof(T) == sizeof(uint32_t),T>::type + byte_swap(T val) + { + uint32_t x; + std::memcpy(&x,&val,sizeof(uint32_t)); + uint32_t y = byte_swap(x); + T val2; + std::memcpy(&val2,&y,sizeof(uint32_t)); + return val2; + } + + template<class T> + typename std::enable_if<std::is_floating_point<T>::value && sizeof(T) == sizeof(uint64_t),T>::type + byte_swap(T val) + { + uint64_t x; + std::memcpy(&x,&val,sizeof(uint64_t)); + uint64_t y = byte_swap(x); + T val2; + std::memcpy(&val2,&y,sizeof(uint64_t)); + return val2; + } + + template<class T> + typename std::enable_if<std::is_floating_point<T>::value && sizeof(T) == 2*sizeof(uint64_t),T>::type + byte_swap(T val) + { + uint128_holder x; + uint8_t buf[2*sizeof(uint64_t)]; + std::memcpy(buf,&val,2*sizeof(uint64_t)); + std::memcpy(&x.lo,buf,sizeof(uint64_t)); + std::memcpy(&x.hi,buf+sizeof(uint64_t),sizeof(uint64_t)); + + uint128_holder y; + y.lo = byte_swap(x.hi); + y.hi = byte_swap(x.lo); + + T val2; + std::memcpy(&val2,&y,2*sizeof(uint64_t)); + + return val2; + } + +} // binary +} // jsoncons + +#endif |